Temporal dynamics of disgust and morality: an event-related potential study

The Implications of Moral Neuroscience for Brain Disease: Review and Update

The last 2 decades have seen an explosion of neuroscience research on morality, with significant implications for brain disease. Many studies have proposed a neuromorality based on intuitive sentiments or emotions aimed at maintaining collaborative social groups. These moral emotions are normative, deontological, and action based, with a rapid evaluation of intentionality. The neuromoral circuitry interacts with the basic mechanisms of socioemotional cognition, including social perception, behavioral control, theory of mind, and social emotions such as empathy. Moral transgressions may result from primary disorders of moral intuitions, or they may be secondary moral impairments from disturbances in these other socioemotional cognitive mechanisms. The proposed neuromoral system for moral intuitions has its major hub in the ventromedial prefrontal cortex and engages other frontal regions as well as the anterior insulae, anterior temporal lobe structures, and right temporoparietal junction and adjacent posterior superior temporal sulcus. Brain diseases that affect these regions, such as behavioral variant frontotemporal dementia, may result in primary disturbances of moral behavior, including criminal behavior. Individuals with focal brain tumors and other lesions in the right temporal and medial frontal regions have committed moral violations. These transgressions can have social and legal consequences for the individuals and require increased awareness of neuromoral disturbances among such individuals with brain diseases.

Different influences of moral violation with and without physical impurity on face processing: An event-related potentials study

It has been widely accepted that moral violations that involve impurity (such as spitting in public) induce the emotion of disgust, but there has been a debate about whether moral violations that do not involve impurity (such as swearing in public) also induce the same emotion. The answer to this question may have implication for understanding where morality comes from and how people make moral judgments. This study aimed to compared the neural mechanisms underlying two kinds of moral violation by using an affective priming task to test the effect of sentences depicting moral violation behaviors with and without physical impurity on subsequent detection of disgusted faces in a visual search task. After reading each sentence, participants completed the face search task. Behavioral and electrophysiological (event-related potential, or ERP) indices of affective priming (P2, N400, LPP) and attention allocation (N2pc) were analyzed. Results of behavioral data and ERP data showed that moral violations both with and without impurity promoted the detection of disgusted faces (RT, N2pc); moral violations without impurity impeded the detection of neutral faces (N400). No priming effect was found on P2 and LPP. The results suggest both types of moral violation influenced the processing of disgusted faces and neutral faces, but the neural activity with temporal characteristics was different.

Individual differences in the early recognition of moral information in lexical processing: An event-related potential study

Previous studies have shown that intuitive moral cognition occurs at an early stage. However, inconsistent findings indicate that moral information is recognized at a relatively late stage. This study uses the recognition potential (RP) as a neural index and simultaneously measures individuals' moral preferences using the Moral Foundation Questionnaire. We aim to investigate how individual differences in moral preferences modulate the processing of morality in the pre-semantic stage and provide some insights to explain the variation in rapid information processing linked to morality. The participants performed an implicit task in which recognizable words depicting geographical names or behaviors related to moral, disgusting or neutral content alternated with background stimuli at high rates of presentation. The results showed that the early recognition of moral information manifested in the RP depended on an individual's moral concerns. Participants with a higher level of endorsement of the harm/care foundation exhibited a greater net moral effect, namely, greater mean amplitudes of the moral-neutral RP difference waves. Meanwhile, only the group that was more sensitive to the harm/care foundation showed a distinctively larger RP for the moral words than for the neutral words. Overall, these findings suggest that the early processing of moral cognition may hinge on individual differences in moral concerns about other people's suffering.

Different timing features in brain processing of core and moral disgust pictures: an event-related potentials study

Disgust, an emotion motivating withdrawal from offensive stimuli, protects us from the risk of biological pathogens and sociomoral violations. Homogeneity of its two types, namely, core and moral disgust has been under intensive debate. To examine the dynamic relationship between them, we recorded event-related potentials (ERPs) for core disgust, moral disgust and neutral pictures while participants performed a modified oddball task. ERP analysis revealed that N1 and P2 amplitudes were largest for the core disgust pictures, indicating automatic processing of the core disgust-evoking pictures. N2 amplitudes were higher for pictures evoking moral disgust relative to core disgust and neutral pictures, reflecting a violation of social norms. The core disgust pictures elicited larger P3 and late positive potential (LPP) amplitudes in comparison with the moral disgust pictures which, in turn, elicited larger P3 and LPP amplitudes when compared to the neutral pictures. Taken together, these findings indicated that core and moral disgust pictures elicited different neural activities at various stages of information processing, which provided supporting evidence for the heterogeneity of disgust.

Delineating the Influence of Emotion and Reason on Morality and Punishment

The present article examines the available literature on the association between emotion, conscious reasoning, morality, and punishment. Although conscious reasoning has traditionally been implicated in moral judgment, contemporary research suggests that emotions play a primary role in moral judgment. This article reviews the different lines of evidence supporting the role of emotion in moral decision-making. Disgust seems to be unique from other emotions in its ability to influence moral judgment. Immorality often elicits disgust, individuals sensitive to experiencing disgust tend to make more severe moral judgments, and experimental disgust inductions can influence judgments about moral violations. However, the extent to which the emotion-moral judgment association extends to decisions about punishment remains unclear. This review considers various concepts, including moral outrage, responsibility, and blameworthiness that may influence the extent to which emotion informs punishment decisions. The implications of these findings for current thinking on morality and punishment, and future directions for research are discussed.